DevTools: Make eslint mandatory and check node.js/npm modules in presubmit

third_party/WebKit/Source/devtools/scripts/node.py

Index: third_party/WebKit/Source/devtools/scripts/node.py
diff --git a/third_party/WebKit/Source/devtools/scripts/node.py b/third_party/WebKit/Source/devtools/scripts/node.py
new file mode 100755
index 0000000000000000000000000000000000000000..6ef6435b0e6d8b2f9ea1ef9efe498307350470b7
--- /dev/null
+++ b/third_party/WebKit/Source/devtools/scripts/node.py
@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+#
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Ensure node.js and npm modules are installed

[dgozman, 2016/09/14 16:37:41]

Let's rename this to install_node_deps

[chenwilliam, 2016/09/15 00:40:11]

Done.

+"""
+
+import os
+from os import path
+import subprocess
+import sys
+
+MIN_NODE_VERSION = 4
+
+
+def main():
+    check_node_version()
+    npm_install()
+
+
+def check_node_version():
+    node_path = which('node')
+    if not node_path:
+        invalid_node_error_message()
+    node_process = popen([node_path, '--version'])
+    (node_process_out, _) = node_process.communicate()
+    if node_process.returncode != 0:
+        invalid_node_error_message()
+    print('Using node.js version: {}'.format(node_process_out))
+    major_version = node_process_out[1]
+    version = int(major_version)
+    if version < MIN_NODE_VERSION:
+        invalid_node_error_message()
+
+
+def invalid_node_error_message():
+    print('Please install node.js v4 or later')
+    print('Download the latest LTS version from nodejs.org:')
+    print('https://nodejs.org/en/download/\n')
+    raise
+
+
+def npm_install():
+    npm_path = which('npm')
+    if not npm_path:
+        print('Cannot find npm, which is bundled with node.js')
+        invalid_node_error_message()
+    npm_process = popen([npm_path, 'install'])
+    (npm_process_out, _) = npm_process.communicate()
+    if npm_process.returncode != 0:
+        print('WARNING: npm install had an issue')
+    print(npm_process_out)
+
+
+# Based on http://stackoverflow.com/questions/377017/test-if-executable-exists-in-python.
+def which(program):
+    def is_exe(fpath):
+        return path.isfile(fpath) and os.access(fpath, os.X_OK)
+
+    fpath, fname = path.split(program)
+    if fpath:
+        if is_exe(program):
+            return program
+    else:
+        for part in os.environ["PATH"].split(os.pathsep):
+            part = part.strip("\"")
+            exe_file = path.join(part, program)
+            if is_exe(exe_file):
+                return exe_file
+    return None
+
+
+def popen(arguments):
+    return subprocess.Popen(
+        arguments, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+
+
+if __name__ == '__main__':
+    sys.exit(main())